Active matrix Spatial Light Modulated displays (SLM) include Liquid Crystal Displays (LCD), electrophoretic displays (EPD), electrowetting displays, cholesteric displays, addressable compressible photonic crystals (such as described in KR20090072146), and Micro Electro-Mechanical System displays (MEMS). These displays operate in one of three illumination modes: backlit, reflective, and transflective which is a combination of backlit and reflective illumination modes. Reflective and transflective illumination modes involve the use of the SLM to reflect ambient light in order to display an image, without the use of a backlight. Advantageously, the displayed image can be viewed easily under bright conditions, while power consumption is significantly lower than backlit display devices.
Color image formation using active matrix SLM currently present challenges for reflective and transflective illumination modes. A patterned color matrix comprising a repeating array of red, green and blue color pixels are typically used to provide a color display. However, as light passes through the color matrix layers and the electrodes associated with each layer, degradation of light quality and parallax issues may result. Ongoing research and development is focused on providing a patterned color matrix capable of providing acceptable image quality.
A need therefore exists for color reflective displays that have high brightness and contrast under bright ambient lighting, including direct sunlight, that can be inexpensively manufactured and can display good quality images.